//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2011 EMC Corp.
//
//	@filename:
//		CXformGbAgg2ScalarAgg.h
//
//	@doc:
//		Transform GbAgg to ScalarAgg
//---------------------------------------------------------------------------
#ifndef GPOPT_CXformGbAgg2ScalarAgg_H
#define GPOPT_CXformGbAgg2ScalarAgg_H

#include "gpos/base.h"
#include "gpopt/xforms/CXformImplementation.h"

namespace gpopt
{
	using namespace gpos;
	
	//---------------------------------------------------------------------------
	//	@class:
	//		CXformGbAgg2ScalarAgg
	//
	//	@doc:
	//		Transform Get to TableScan
	//
	//---------------------------------------------------------------------------
	class CXformGbAgg2ScalarAgg : public CXformImplementation
	{

		private:

			// private copy ctor
			CXformGbAgg2ScalarAgg(const CXformGbAgg2ScalarAgg &);

		public:
		
			// ctor
			CXformGbAgg2ScalarAgg(CMemoryPool *mp);

			// dtor
			virtual 
			~CXformGbAgg2ScalarAgg() {}

			// ident accessors
			virtual
			EXformId Exfid() const
			{
				return ExfGbAgg2ScalarAgg;
			}
			
			// return a string for xform name
			virtual 
			const CHAR *SzId() const
			{
				return "CXformGbAgg2ScalarAgg";
			}
			
			// compute xform promise for a given expression handle
			virtual
			EXformPromise Exfp(CExpressionHandle &exprhdl) const;

			// actual transform
			void Transform
					(
					CXformContext *pxfctxt,
					CXformResult *pxfres,
					CExpression *pexpr
					) const;
		
	}; // class CXformGbAgg2ScalarAgg

}


#endif // !GPOPT_CXformGbAgg2ScalarAgg_H

// EOF
